Caption: Hard corals. These reefs in the Gubal Straits of the Red Sea are the most northerly coral reefs and have some of the best examples of reef building species. The predominant strong north winds produce shallow, highly oxygenated water, while the persistent wind forces surface water south, inducing a nutrient rich upswelling ideal for coral productivity. The relatively sheltered Red Sea does not have the oceanic swells that modify coral growth in more exposed seas